We report a case of asymptomatic intraosseous ganglioneuroma of the ilium, which was initially misdiagnosed as polyostotic fibrous dysplasia. Our patient presented with multiple asymptomatic skeletal lesions. Despite extensive work-up of our patient to rule out metastatic disease, we were unable to find a primary source; biopsy showed intraosseous ganglioneuroma of the ilium. To the best of our knowledge, we report an exceedingly rare pathologic entity; only 3 cases have been described of intraosseous ganglioneuroma from spontaneous cytomaturation of metastatic neuroblastoma. Knowledge of the natural history of ganglioneuroma is limited, but patients with primary and multifocal disease appear to have benign histologic tumor appearance and excellent prognoses. Similar to previous studies, the rarity of this tumor and its nonspecific radiographic and clinical presentation resulted in the correct diagnosis only after histopathologic analysis. Because intraosseous ganglioneuroma may mimic fibrous dysplasia it should be considered in the differential diagnosis of benignappearing skeletal lesions, particularly if the patient has a history of neuroblastoma.